Meta-analyses and the Problems of Duplicate Publication and Plagiarism

A chart showing happiness levels by country, generated from a meta-analysis (public domain).

“Meta-analysis refers to the application of quantitative methods to the problem of combining results from different analytic studies” [1].

But what happens when some misconduct occurs, and the same study is published twice?

According to a Choi, et al.,

“With the increasing use of meta-analysis, duplicate publication of original research is particularly problematic. Duplicate publication can result in an inappropriate weighting of the study results” [2].

Here [below] is a case of apparent duplicate publication that I was alerted to recently. Both articles appeared at about the same time — the end of 2013 or the beginning of 2014. Each article has six authors. Four authors are common to both articles, and each article also has two authors that only appear on that one article.

One might argue that this is not duplicate publication but plagiarism, because the authors are different.

Although the titles differ, the text in the two articles is mostly the same. As far as I know these two articles haven’t been used in any meta-analyses. Both are published open-access.

In cases like these, the publishers can be victims of the authors submitting papers to multiple journals at once. Plagiarism checks come up negative because the plagiarism database has not yet been populated with the article’s text.

I agree with Choi, et. al. and think that the increasing amount of duplicate publication/plagiarism may threaten the validity of meta-analyses. Because it is so easy to get published in predatory journals, they may contain more duplicated and plagiarized articles, compounding the problem.

Post navigation

17 Responses to Meta-analyses and the Problems of Duplicate Publication and Plagiarism

This topic is certainly imporant. Luckily, not many putative double publications seem to have passed the meta-analystic filters, which speaks well of most scholars performing them. In fact, if statements such as PRISMA are followed and the work is done carefully enough doublets should come up in the routine process of meta-analysis..

I have two issues with the Choi et al. paper that I would have brought up had I reviewed their manuscript.

First, it would have been important to add analysis and not be so descriptive: discuss why the meta-analyses did not notice the duplication while Choi et al. did. Were they for some reason harder to detect? Did these studies adhere to specific guideline?. Would those guidelines need amendments? Were these meta-analyses performed with generally less rigor? Because Choi et al. seemingly do not identify the partially faulty papers, we can not make a judgement about these aspects. Post publication peer review of their findings and conclusions is impossible.

Second, they do not mention whether the meta-analyses that included duplicate publications and thus were biased according to their opinion have been brought to the attention of the respective journals and editors for consideration of publishing a correction or even a retraction. If not, have the authors pointed out the alledged faults in PubPeer or a similar forum to fellow scientists. If not, they likely have partially failed to maintain scientific integrity.

In my field (road safety) we often need to consider the “grey” literature as well as peer reviewed publications, and this problem is common. It is not unusual for a non-peer reviewed conference paper to be recycled between conferences, or to be turned into a peer-reviewed publication with sometimes few changes. None of this is necessarily malpractice, because passage into the “true” scientific arena is seen as being a peer review publication, and many of the writers are practitioners rather than academics, but it means that we have to be watchful for duplication when reviewing literature or conducting meta-analyses. I guess it’s clear that this has to apply to the peer reviewed literature as well..

This problematic phenomenon is not only restricted to “predtaory journals”. Take Springer Science and Business Medium, for example. There is a wealth fo duplicated papers, often in the form of a journal article which is then recycled as a book chapter (with or without the same title, and some restructuring). Although in most cases neither the journal article or book chapter reference each other, making them true cases of plagiarism, Springer claims that this is not unethical. However, it has zero difference to a case where the author manipulates the duplication to achieve a double metric. Why, in the case of Springer, is is ethical to manipulate the literature with duplicates in order to generate more revenues when it is not in the case shown here? What morally superior authority does Springer have to claim that “their type” of duplication is ethical while that imposed upon authors is not? A clear case of different strokes for different folks. To give an example of a prominent case in the plant sciences (there are potentially dozens or hundreds in Sprnger archives):
Jeffrey Adelberg; Plant Cell, Tissue and Organ Culture
June 2005, Volume 81, Issue 3, pp 359-368
Efficiency in thin-film liquid system for Hosta micropropagation

So now open access publishing is causing a chain reaction. First open access publishing is polluting the existing literature and if that was not enough it will pollute the future studies especially meta analysis. Will there ever be an end to all this?

I agree with Ole, Ole! that this problem is not restricted to open access or predatory journals. As a Clinical Coordinator for a hospital, my significant other spends a great deal of time evaluating the clinical literature for drug therapies, and finds that this is a problem that one always has to be watching for. He has found numerous instances of drug studies that seem to use the same patients; they just differ slightly in the Study Title and rearrange the authors. The authors of meta-analyses need to be particularly vigilant to avoid skewing the data.

We pay the attention to this problem earlier (1).
The cure is to meta-analyse the studies, not articles. Duplicate publications are frequent, in all kinds of journals. If meta-analysis is careful, the author may need to extract the different data from different publications, originated from the study.
Most important is that the author of the systematic review/meta-analysis is in the unique position to find the all kinds of misconduct/discrepancies while analyzing the data. “Normal” readers would never find duplicate publication and/or manipulation, just because they do not read the totality of papers at once.
I believe that it is the obligation of the reviewer to look at possible misconduct and expose шею
(1). 1. Vlassov V, Groves T. The role of Cochrane Review authors in exposing research misconduct [editorial]. The Cochrane Library 2010 (8 Dec). http://www.thecochranelibrary.com/details/editorial/886689/The-role-of-Cochrane-Review-authors-in-exposing-research-and-publication-miscond.html#_16

I would like to inform you that the paper was retracted from Macedonian Journal of Medical Sciences:
Retraction

The article published by Ilankovic et al., 2013 [1] has been retracted by Editor-in-Chief because corresponding author published the similar paper in Psychiatria Danubina in 2014 [2]. An internal investigation has raised sufficient evidence of the originality in the first paper [1] and self plagiarism in the second paper [2]; as such, we retract this article from the literature on request by corresponding author and in accordance with guidelines and best editorial practices from the Committee on Publication Ethics. We apologize to our audience about this unfortunate situation.

As a peer reviewer, I had a case where a proposed paper (in English) has been published earlier in Portuguese, with the order of the author’s names shuffled around and some minor changes made to the content.

I would like to inform you that the paper was retracted from Macedonian Journal of Medical Sciences:
Retraction

The article published by Ilankovic et al., 2013 [1] has been retracted by Editor-in-Chief because corresponding author published the similar paper in Psychiatria Danubina in 2014 [2]. An internal investigation has raised sufficient evidence of the originality in the first paper [1] and self plagiarism in the second paper [2]; as such, we retract this article from the literature on request by corresponding author and in accordance with guidelines and best editorial practices from the Committee on Publication Ethics. We apologize to our audience about this unfortunate situation.

Once article about original research can not be plagiat or autoplagiat from the author! Then all article about Penicilin are plagiats of A. Fleming work, all copies of music and literature of famous componist and writer are PLAGIAT!?

For meta analises are not the problems the simmilar articles, than the not original, constructed, virtual research articles without control studies! The problem is not in form, in text, than in falsificate of many research without real research, sample, data….!

“The American Psychological Association (2010) explains how plagiarism differs from self-plagiarism: “Whereas
plagiarism refers to the practice of claiming credit for the words, ideas, and concepts of others, self-plagiarism
refers to the practice of presenting one’s own previously published work as though it were new” (pg. 170).
As Roig (2006) suggests, self-plagiarism occurs “when authors reuse their own previously written work …..”
Then all texts from Albert Einstein about Theory of relatitivity and Isak Newtn thesis about gravitation are AUTO PLAGIATS (SELF-PLAGIARISM)!!? What a nonsence and stupidity! It is the new waz to stop and control the new original research, creativity and the new scientific ideas! First from editors, seciond from reviewers (thay make plagiats of original ideas for self), and now from new “head hunters” who moralistic try to block the new scientific ideas and sale only the profitable theories, drugs, and ordered and prepaid “researches”.

You can make a retrospective and find many never profeed and apllaid so called research, without any demanty of the editors or the authors, and without any control study (replication of experiments), what is the basis of real scientific work.